National party computers today keep track of where you live, your phone number and e-mail address, whether you vote, your willingness or refusal to make political contributions, your interests, ethnic background, reading habits and church attendance. Some files contain hints about your sexual preferences, whether own a gun and your views on abortion and other issues.

Civil liberties activists, who used to worry mostly about the FBI, the CIA and lately the Department of Homeland Security snooping into citizens' private lives, now see the political parties as a threat - and not just to privacy, but to the democratic process.

Unbound by the constraints that often apply to law enforcement agencies, the parties are segmenting citizens into psychographic databases according to individual attitudes, behaviors and beliefs - all the better to target them for communications by mail, phone or direct contact to extract money and votes.

Party leaders say they are just doing more efficiently what they've always done at the grass-roots level.

"It's not about the number of names but how much data you can put behind each name that makes the difference," said Eddie Mahe, a veteran Republican campaign consultant.

Invade privacy? "We would never do that," said Iowa Democratic Chairman Gordon Fischer. "We're very sensitive to privacy concerns."

"Think about the possibilities for abuse, for manipulation - democracy suffers when you tailor your message 12 different ways depending on who you want to reach out to," she said. "The data that can be purchased is mind- boggling."

Democratic National Chairman Terry McAuliffe sees Demzilla as a means to win back the White House in 2004. The electronic depository contains information gleaned from commercially available consumer databases, the census,

records of the National Committee for an Effective Congress and state party organizations.

To demonstrate Demzilla's capabilities, McAuliffe turned to Lina Petty, "our director of targeting." With a few computer keystrokes, Petty identified all Missouri voters who have contributed more than $100 to the party, and an additional 2,886 citizens in that state who have indicated "an interest in gay and lesbian issues."

Said McAuliffe, "We can go right down to the county and precinct level and pull up any person who now lives in any of those precincts . . . with high- quality lists for targeting, testing, fund raising and organizing for a master mobilization effort in 2004."

"If full and equal participation in the public sphere is a fundamental requirement for the realization of the goals of the idealized democracy, then the use of segmentation and targeting by political consultants is a serious threat," Gandy said. In his view, the decline in voter participation "is undoubtedly the result of a strategy of focusing campaign resources on that segment of 'likely voters' that are likely to vote the right way."

But political parties engage in segmenting and targeting for precisely that reason, said James Dyke, a spokesman for the RNC. "Voter Vault," the GOP's central database, is shared with state and local candidates to help them identify supporters based on the issues important to them.

Greg McNeilly, the GOP's state executive director in Michigan, said the RNC has "revolutionized how we use voter lists with the Voter Vault program."

Teams of volunteers equipped with handheld computers record information from conversations they have as they canvass neighborhoods. Rather than asking about specific programs like the president's tax cut or faith-based initiative,

data gatherers are urged to focus on "fundamental political ideology questions, like guns, abortion, because those type of things have a long shelf life."

The information is then fed directly into Voter Vault.

"The best example of useful data is magazine subscriptions," McNeilly said. "Somebody who reads Mother Jones is likely to be a Democratic voter, and somebody who reads the National Review is more likely to be a Republican."

Iowa's Democratic activists also carry handheld computers as they canvass households, said Mark Daly, the party's state communications director.

"They go door to door to identify supporters and how they feel about issues like the economy, health care, the right to choose, education," Daly said. "At the end of the night, we go back to the computer and log on, and all information . . . is then sent up into the database, which already contains a list of all the voters in the state and all the information we have obtained on them - their mailing addresses, cell phone and home and work telephones, e- mail address, voting history."

The data is shared by computer link with Demzilla.

Beyond what the parties gather from the voters themselves are the mountains of detail that can be purchased through commercial data-mining companies.

One such firm, I-Centrix of Rensselaer, N.Y., sells a service called VISION,

for Voter Information System Integrated Online Network. An online brochure explains what the system can do:

"If a customer wanted a list of all 45-plus Italian men, registered Democrat, with a median income over $70,000, voting in presidential elections, with a phone number, living in the 3rd election district in the City of Troy, N.Y., the customer would make the appropriate menu selections for that target group and press the 'submit request button.' A count would be given (125 voters). . . . The only data that would appear is: name, address and phone numbers. All supporting data remains hidden."

"We are the cutting edge of this technology," said Jason Powers, vice president for business development, who worked for the RNC in developing its national database. "We'll process 5 billion records this year."